Starting mechanism fbr automobiles



APPLICATION FILED APR. 19. l9l7.

Patented Aug. 2, 1921.

INVENTOR Fran/r Conrad WITNESSES: iwaam.

ATTORNEY UNITED STATES PATENT OFFICE.

FRANK CON RAD, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

STARTING MECHANISM FOR AUTOMOBILES.

Specification of Letters Patent.

Patented Aug. 2, 1921.

Application filed April 19, 1917. Serial No. 163,179.

My invention relates to startingmechanisms for automobiles and it has particular relation to such mechanisms as embody dynamo-electric machines and means for controlling the engagement of gear wheels for operatively connecting the dynamoelectric machines to the shafts of internalcombustion engines. 1 I

The object of my invention is to provide a simple and automatic arrangement whereby an operative connection may be established between the armature ofa dynamo-.

electric machine and an engine shaft by the reciprocation of parts of comparativel light Weight While little or no torque is e ectlve to rotate the armature.

It has been proposed to employ motors having displaced armatures which. recipro cats to effect the meshing of coacting gear wheels but they possess certain disadvan-v tages in that they require the use of complicated switchin mechanisms for preventing the rotation o the armature untll the gear wheels are placed in mesh. This arrangement is necessary because, in the displaced position of the armature, the torque is sufficiently high to rotate the armature at a comparatively high rate of speed before the. gear wheels are completely meshed.

In the operation of motors having armaturcs of the character described above, the reciprocatin parts are very heavy and the shock resulting from the engagement of the parts, in case the coacting gear teeth are not in register, may seriously damage the gear teeth. An excessively long commutator must be provided in order that the brushes may be in engagement with it throughout the path of movement of the armature.

Patent No. 1,246,057, issued Nov. 13, 1917 the assignee of which is also the assignee of the present application, covers an arrangement comprising a series-wound electric motor and an electromagnet in series relation to the motor for actuating a pinion into and out of engagement with the fly-wheel gear.

A short-circuited winding is inductively related to the series field-magnet winding of the motor in order to automatically prevent the magnetic field of the motor from attaining its normal strength except after a predetermined period for the purpose of enabling-the electromagnet, to effect the meshing of the gear wheels before the normal torque is applied to the armature. This arrangement has proven successful in practice but it possesses a disadvantage which does not obtain inthe present invention. In the former arrangement, thev shortcircuited or damper .winding occupies considerable space adjacent the -field-magnet poles of the motor which might, otherwise, be available for an increased number. of turns of the field-magnet winding.

According to the present invention, I pro- -vide a non-inductiveshunt path for the seriesfieldi-niagnet winding of the motor that is of high resistance relatively tothe fieldmagnet winding. The pinion, which is actuated into and out of mesh with the fly-wheel gear, is connected to the core member of the electromagnet b means of a rod that is slidably mounted within a tubular armature shaft. ,When the circuit of the motor is closed, a rush of current occursand the value of the inductance of the series fieldmagnet winding is sufiiciently high to cause a. large portion of the current to traverse the high-resistance shunt path. The fieldmagnet winding is, therefore, energized gradually and the meshing of the gear wheels is effected before the armature is rotated at such speed that the meshing opera tion is rendered difiicult.

The details of my invention will be described in connection with the accompanying drawing, in which Figure 1 is a side view, partially in elevation and partially in section, of a portion of an engine fly wheel having my invention associated therewith. Fi 2 is a diagrammatic view of circuits an apparatus embodying my invention.

Referring particularly to Fig. 1, an engine fly wheel 1, only a portion of which is shown, is provided with gear teeth 2. An electric motor 3 has a field-magnet frame 4 which may be secured to any suitable stationary part ofa motor vehicle. The motor has field-magnet pole pieces 5, each of which is provided with a coil 6 of a series field magnet winding.

such dpbsiti'on that.

a net coil 18.

"eieetrema'ghet 16 thttt: is located hr an extendedpo'rtion 17 oftlie'inotorrasifngafld-is in axial itlin'mfit with the armatiireshzi'ft i).

The electroihtlmietcdmprises a coil lSthat is in series with the series fielthrriagnet Windi e at the motor. Yi'i h "an iilztl gtl ptiitlfiii 19 Whidll (fOilSititittes tlieinoi ahlecore nieniher'o'f the electromagnet. A'ts'pfiiigfll), whicli is ihter'po'sed between th -car memheh i and ohe ci' of the casing I7, tends tor'nainteiii'therdti 11 in V the pinlon 12 is disenage hem the gear te'e'th'Q. 'The 'tiiotbr is rovided with a terhlihel me1hbei- 21 which 15 confre ctedto'the coil lsof'tli'e ei'eccreme net. Theother terminal of the c'oil 18is cohiie-ctedto the meter windings hy'asuitable conductor 22.

'the electrical eonheetinhs of the motor" and the eleetrpmeghetiare diagrammatically illustrated in' Fi 2. The rriottihfcitcuit'comprises'th'e armature fiel d inagntfwifidihg' e, a manusnyo erabie sititelijQ, asto'iage battery 25 and the triag- Oneof the battery 't'ern'iihals and one ofthe motorrterminalsf aregr'oun'(led a single-wire system bein /employed. A non-inductive resistor 26 is permanently connected between the terminals of the 'series 'field mfzig'net windin 6. The ohmic" re sistance of the resistor may be, for examp le,--ten times that ofthe fieldmmgnet winding. 7

To s'tart'the engine, the operdtor closes the swit ch24 to complete the meter circuit. The coil 18 i'sinimediately energizecl to actuate the core member 19, the rod 11,:md the/pinion 12 to the lett is viewed infFig. 1 ag'fiihst the force of the sp'ring 20. The series-fieldmag'het Winding26 will :ils'o'h'e eiierg'izfid hut to-a relatively small degree because the inductive character of the winding causes a eonsidera le portion ofthe current to tempo- 'r arily traverse the shunt. path comprising the resistor 26. By r'e'ason of the high resistance of the shunt path, the current through the series ficld m'agnct winding increases gradually and'theto'r'que of the motor increases toja corresponding degree.

The effect of tliver'ting a large portion of the current traversing the motor eirc'u'it'is to tlel'ay or modify the iieimahopera'tioii of the motor while the geiir Wheels are he'ing meshed. The effect is. therefore, to materially limit the field ilux of'the motor when Therod 1i isprovided wihdihgi 23, "the series the circuit is initially closed, so that a very slight torque, if any, is effective to rotate the piiiion 12 While it is heing' iieshed With the gear teeth 2. The iiorinal torque of the motor is available,- however, substantially upon the complete meshing of the coasting gear'teeth. The fly Wheel is thereupon r0 tated to crank the engine.

the eiigihe starts under its own power, the motor circuit may he opened at the switch 24. Theeoillflis then deeherglified'ahd the spring QUfWhich has been" comressed; Will'the'n rtuiti the core member 19, t lie r'od' 11 find the pinion 12tbthe'ir respective illustrated pushiehs; with the pinion 'aiseh' glidfr'ofirthflj?wheel l'.

17f he operator fails te'o' en the motor circuit immediatelyafti the en l'ne s'tlirts, "theihotor w n he dhvehevhiepifiiy mermiii'g speed; 'T-he ehhhter e'ietremhtive "force shah value that th'epull exetted liythe coil is is less thari the force bfthe spring -20,

whereupon "the foil 11' is shift'fl to its "he rmal position and thepinion' l2 isfdiseiigttfgcd from the gear teeth 2. It is ehihchsytim-efore; thathoflemzigehihybe c'ziiisecl byfhii- 'hrewoe ehfi eswheh at the p oper time.

. 'Ainon'g orher edvehmges' ,pes-sessed hy a mechanism *ce strueted in"1tt :6rdnn 'e f 'iith my ifiventiofl, itmhy 'be notetl' that the reciprocatlng'parts are light in Wiightan'd 'are not an essential pziit ofa dj h'aiiio-electiic machine. Be'caiise jdfthis"latterfadt; it is not 'necessai toprovide'a 'comnihtzitor ofamion Tii'ahlen h'ol rorresif'rxhge the lhiitor casin and hearings. 'iiiechaiiism operates an 'tdr'natically, upoiithe cldslhg of a simple switch, to effect the meshhig f' the pinion fi'iiith tliefl y-wheel gear while little or no torque is eiiectii' e"to' rotzifte the pinion and .the amm r ter ueis'eheetiv when the gear wheels are completely meshed.

Theindlittive character of the hem-mag whetwihdihigw muse e eurreht of" alifiotinal value to traverse the shunt resistor temporarily. The. high res-seams 6f "-tlie"shunt zpetheeus'esie gradual ehangeih'the relative values of currents traversihg 'the eeing circuits. Durl'ngjthe eperahenei'rhe 'ino'tor Yto cr'ahk the engine, fa comparatively small current'traver'scsthe 'shhnt path and the loss in etier' by redso'n' of the shirt path is practical y he -ligihle. eeeupi s iittle'cr'no sphce that might be utilized for the coils'of the series field-triagnet winding.

While I hhve'sh' 'wnaiid described a noninductive pathih e um: "relation te thefieldmagnet; winding of the motor, it is understoodthetsuch modifications ma be made as fall within the scope of the appended claimswithout departing from the spirit of my invention.

e shunt resistor I claim as my invention:

1. In a startingmechanism, the combination with a pair of coacting gear wheels, and means comprising an electromagnet for shifting one of said gear wheels into and out of mesh with the other, of an electric motor operatively connected to one of said gear wheels, means for substantially simultaneously controlling a circuit comprising said motor and said electromagnet, said motor havin a field-magnet winding, and a non-inductive path of relatively high re sistance in permanent parallel relation to said field-magnet winding, whereby the energization of said field-magnet winding is delayed relatively to the operation of said electromagnet.

2. In a starting mechanism, the combination with a pair of coacting gear wheels, and means comprising an electromagnet for shifting one of said gear wheels into and out of mesh with the other, of an electric motor energized simultaneously with said electromagnet and operatively connected to one of said gear wheels, said motor having a fieldmagnet winding, and a non-inductive resistor of relatively high value permanently in shunt relation to said field-magnet winding, whereby the energization of said field-magnet winding is delayed relatively to the op eration of said electromagnet.

3. In a starting mechanism, the combination with a pair of coacting gear wheels and an electric motor operatively connected to one of said gear wheels, said motor having a field-magnet winding, of means compris ing an electromagnet having a coil in series with said motor for actuating one of said gear wheels into and out of mesh with the other, and means for permanently providing a path in shunt relation to said field-magnet winding whereby the ampere-turns of said winding are materially reduced temporarily upon the initial closing of the normal circuit of said motor 4. In a starting mechanism, the combination with a pair of coacting gear wheels and an electric motor operatively connected to one of said gear wheels, said motor having a field-magnet winding, of means comprising an electromagnet having a coil in series with said motor for actuating one of said gear wheels into and out of mesh with the other, and means for permanently providing a path in shunt relation to said fieldmagnet Winding, said path being of low inductance and high resistance relatively to said field-magnet winding.

5. In a starting mechanism, the combination with a pair of coacting gear wheels and means for shifting one of said gear wheels into, and out of, mesh with the other, of an electric motor operatively connected to one of said gear wheels, common means for controlling said shifting means and said motor, said motor having a field-magnet winding and a non-inductive resistor of relatively high value permanently in shunt relation to said fieldmagnet winding, whereby the energization of said field-magnet winding is delayed relatively to the operation of said means.

6. In a starting mechanism, the combination with a shiftable gear wheel and shifting means therefor, of an electric motor for rotating said gear wheel and having a fieldrnagnet winding, common means for controlling said shifting means and said motor, and means ermanently in shunt circuit relation to said winding for delaying its energization relatively to the operation of said shifting means.

In testimony whereof, I have hereunto subscribed my name this 3rd day of April,

FRANK CONRAD. 

